The functional significance of amylase polymorphism in Drosophila melanogaster I. Properties of two amylase variants

✍ Scribed by A. J. W. Hoorn; W. Scharloo

• Publisher: Springer Netherlands
• Year: 1978
• Tongue: English
• Weight: 494 KB
• Volume: 49
• Category: Article
• ISSN: 0016-6707
• DOI: 10.1007/bf00120563

✦ Synopsis

Properties of amylase of two strains homozygous for two different amylase variants of Drosophila rnelanogaster were determined. Amylase of larvae and adults of both strains showed a pH optimum around pit 7.0. The Amy I enz)alae showed a higher temperature stability. They differed in maximal activity (for Amy 1 Vma x = 26.2 mU/9, for Amy4, 6 Vma x = 128.9 mU/ 9) and Michaelis constants (for Amy 1 K m = 0.09% starch, for Amy a,6 K m = 0.25% starch). This means that the activity difference measured at saturating substrate concentrations will not vanish or will not be reversed at lower substrate concentrations. This supports the hypothesis that this difference in amylase activity will cause a selective advantage when the two strains compete for food and starch is a limiting factor.